“四深”微生物的地质作用——从气候环境变化到生态灾难

“四深”微生物是指深海、深地、深空和深时环境的微生物,特别是细菌、古菌、真菌、病毒等。人们对“四深”微生物的了解非常有限,是亟待突破的地球生物学前沿领域。“四深”微生物的研究对理解地球生命起源、界定生物圈的边界条件、促进地球科学与生命科学以及行星科学之间的交叉融合具有不可替代性的贡献。随着我国深海、深空、深地等重大工程计划的推进,一系列与“四深”微生物有关的前沿科学问题不断提出,包括地质微生物与气候环境的相互作用、地质微生物的生物安全与生态安全、地质微生物参与的隐匿地质过程等。特别是,“四深”环境活性氧自由基对微生物的影响、地质病毒对生物演化和地质过程的影响等前沿领域都亟待突破。活性氧自由基能对生物分子、细胞、组织和器官,乃至整个生物圈的演化以及微生物地质作用都产生重要影响。病毒引发了现代和近代诸多全球性疫情爆发,地质病毒则可能对生物的背景灭绝和大灭绝以及一些地质过程产生影响。     

金刚石的撞击成因与找矿新思考

<正>“深地、深海、深空、深蓝”是代表科技发展前沿和我国战略发展方向的重要领域。其中,“深地”和“深空”是地球和行星科学研究的重点领域,是解决地球科学重大基础理论问题、探索太阳系演化历史等科学问题,以及保障国家能源资源安全、拓展人类生存空间、保障人类社会可持续发展的重要领域(欧阳自远等, 2002; Wilson et al.,2004; 李三忠等, 2010; 郑永春等, 2011; 郑永春和欧阳自远, 2014; 杨经绥等, 2021)。     

深海热液生态系统特征及其对极端微生物的影响

深海是地球上最重要的极端环境之一,发育了数量巨大的极端微生物。它们独特的生存环境、生理结构、代谢机制和共生关系成为探讨生命起源及寻找外太空生命的关键。尽管从生物学角度对极端微生物已开展了大量研究,但深海热液系统对极端微生物演化的影响仍不甚清楚。因此,在总结深海极端的理化环境和地质环境特征的基础上,分析了海底热液活动的分布特征、形成机理及其对周围生物群落种类、分布和演替规律的巨大影响。重点探讨了热液环境下各种极端微生物的生命形式及其对深海营养物质循环和生态系统演化的重要意义。目前,极端环境与生命过程的研究仍处于初级阶段,亟待加强深海原位探测和分子生物学技术的研发以及多学科交叉研究。     

再谈古生物学向地球生物学的发展:服务领域的拓展与创新

地球科学前沿研究为社会服务是一个永恒的主题,这在当前全球化背景下尤其迫切.古生物学作为一个受人瞩目的精品学科,在向地球生物学发展过程中,其服务领域正不断地拓展和创新.系统地总结了当前地球生物学在全球变化和油气资源两大领域的应用与拓展,以及在关键带和深地两大领域的创新性发展.在全球变化领域,藻类、古菌、细菌等地质微生物的脂类不仅能够用于估算古温度,还可以记录干旱等极端古气候事件,从而实现古温度与古降水信号的分离.地球生物学已经从探索生物对环境的响应深入到生物对环境的作用.地球生物学也在评价烃源岩、储层等常规油气资源领域得到广泛的应用,但当前其更重要的应用表现在页岩气等非常规油气资源领域,包括地质微生物形成页岩中的纳米孔隙,形成易于压裂的长石、石英等矿物.在关键带研究领域,地球生物学可以解剖碳循环与水循环之间的内在联系.聚焦于地质微生物功能群的关键带地质微生物调查,不仅可以查明污染物的分布和污染程度,还可以为环境修复提供技术方法.而在深地研究领域,为拓展对地下空间的利用,需要充分利用地下工程对地下微生物开展调查和研究,以查明地下环境中有害或者有益的微生物功能群分布及其地质作用.      

“深时”（Deep Time）研究与沉积学

近百年来全球气候正在经历一次以变暖为主要特征的显著变化,人类文明的发展迫切要求我们对这种变化的发展趋势及其环境与资源效应有更加深入的了解。仅仅对现代和第四纪气候研究是有局限性的,全面了解地球表层及气候系统需要研究整个地质历史时期地球表层系统的发展演化。基于这样一种需求,从沉积记录研究前第四纪地质历史时期的地球古气候变化及重大地质事件,并为未来气候预测提供依据的“深时”（Deep Time）研究计划在国际地球科学界逐渐形成。“深时”研究将聚焦地球气候系统中的重大科学问题,通过地质历史时期极端气候事件探讨气候变化的极限和速率、大气成分和大洋成分变化、大气环流和大洋环流以及生物圈、固体地球与太阳的联系等,最终揭示地球气候系统与地球系统的联系。“深时”研究将通过解译、定年和模拟的基本方法,发展完善大陆科学钻探项目,获得保存良好、高分辨率的沉积记录是重中之重。可以预见,“深时”研究将与“深空”（Deep Space）、“深海”（Deep Sea）和“深部”（Deep Interior）研究计划一样,成为未来国际和国内地球科学重大研究领域。同时,在开展“深时”研究过程中,沉积学也将扮演核心学科的角色发挥重要的作用。     

极端环境下的微生物及其生物地球化学作用

极端微生物是地球生物圈的重要组成部分。极端微生物的地球化学定位在微生物学与地球化学以及一些相关学科的交叉点上,最近10年已经发展成为地质生物学研究的热门领域。对极端微生物的研究不仅有助于回答生命起源、生命极限、生命本质甚至其他生命形式等生命科学问题,而且其生物地球化学作用在地球系统科学研究中具有重大科学研究价值,对揭示生物圈与地圈协同演化的奥秘、认识生命与环境相互作用规律及地球的化学演化提供重要证据。总结了嗜热菌、嗜冷菌、嗜酸菌、嗜碱菌、嗜压菌、嗜盐菌以及抗辐射菌的主要类群,论述了极端微生物适应环境的机制,探讨了极端微生物的生物地球化学意义。作者预测未来将会在生物标志化合物研究、同位素地球化学分析和分子生物学综合研究的基础上协同推进极端微生物地球化学学科的发展。     

现代大洋不同热液区地球化学特征及微生物成矿

生物圈将地球其他圈层有机地联系在一起。已有研究发现,地质与生物密切相关,地质过程为生物提供生活场所、能量和营养物质,生物活动改变地质过程,如微生物改变洋壳和海洋的化学组成,生物地球化学循环改变元素的迁移。研究发现,陆地上已发现的一些矿床,是生物成矿的或与生物作用有关。微生物在现代大洋中的多金属结核和结壳的形成起到重要作用。对大     

地质微生物学及其发展方向

地质微生物学是在20世纪末发展起来的新的地学分支,主要研究地质环境中的微生物活动过程及其形成的各种地质地球化学记录。通过对现代及地质历史上的各种地质环境,包括极高温,高压,极端酸性,碱性,高盐度,极高放射性,地球深部等环境中微生物的生存和演化,及其和地质环境的相互作用而形成的各种地球化学记录的研究,探讨微生物在过去、现在和将来对生命活动最重要的元素(C,H,O,N,S,Fe等)在全球或局部尺度上的循环作用,从而对微生物的风化作用、成矿作用、地质环境下的微生物生态链及其环境的研究提供重要的科学证据。微生物与矿物的相互作用、极端环境下的微生物和生态及分子地质微生物学是当前地质微生物学研究的重要方向。     

深海微生物多样性形成机制浅析

随着全球人口、资源与环境问题的加剧,人类把目光投向海洋。深海包含在极酸、极碱、极热、极冷、高盐、高压等极端环境下能够生存繁衍的微生物。与陆地微生物比较,它们可能具备某些不同的代谢途径和遗传背景。对极端环境微生物生存与适应机制的研究将加深我们对深海微生物乃至深海生物圈对全球气候影响的理解,也将促进我们对深海微生物资源和深海矿产资源的开发。在综合以往对各种极端环境下微生物研究的基础上对深海微生物的生存及适应机制进行了分析与阐释,为深海微生物的研究提供参考。     

大气圈氧气上升与生物进化:一个重要的地球生物学过程

以生氧光合作用为主造成的大气圈氧气上升,与生物进化存在着密切的成因联系。在大气圈氧气含量明显上升之前,微生物在地球大气圈演化中可能起着主要作用,形成了埃迪卡拉纪之前的微生物世界;甚至到今天,这些细菌以及其他的微体藻类,一直在向地球的大气圈提供氧气,而且在海洋中进行着艰苦的固氮作用。早期很少受到动物影响的生物圈,与现代动物所占据的生物圈(后生动物世界)明显不同,这个转变随着埃迪卡拉纪—寒武纪器官级别的动物辐射而发生,动物辐射造成了宏观生态和宏观进化表现的根本性变化。因此,地球大气圈的氧气上升,实际上是一个复杂的地球生物学过程;追索这个复杂的地球生物学过程所产生的环境变化及其与生物进化与革新之间的成因联系,对深入了解地球复杂的演变历史将提供一些重要线索和思考途径。     

For the deep biosphere,the present is not always the key to the past: what we can learn from the geological record

Microbial life below the Earth's surface (the deep biosphere) has probably varied significantly since the Archaean. Reconstructing changes in deep biosphere activity over geological timescales is necessary to understand its role in biogeochemical cycling. Even for the last few million years, such changes are often not captured by studying the distribution of present activity. However, several studies using samples from scientific drilling have revealed mineralogical, geochemical, isotopic and fossil organic molecule imprints in the sedimentary record that document rather different past deep biosphere conditions. Changing deep biosphere conditions can also be simulated using geochemical models. While some processes occurring in the past can be understood by comparing them with the present deep biosphere, others lack any modern analogue – they are defined as non‐actualistic. A non‐actualistic consideration of the deep biosphere is therefore essential for a better understanding of how Earth and life co‐evolved through time.     

地球环境与生命过程

生物圈是地球系统中唯一具有生命活动的圈层,生物圈及其与各圈层之间的相互作用对地球环境变化起着巨大的推动作用。因此,有关生命过程与地球环境相互关系的知识对于人类理解地球系统以及利用地圈、水圈和大气圈资源至关重要。地球环境与生命过程研究的内涵就是研究地球环境与生命过程相互作用中的各种化学、物理、生物过程,以及其在地圈、水圈、大气圈、生物圈各子系统之间发生的相互作用,增进对地球系统的理解和认识,区分人类活动与自然过程在全球变化中的作用,评估气候与环境变化对生命过程的影响及其反馈作用,揭示生命过程对于地球环境的适应性及其调控机理,为科学地管理地球,确保地球系统的可持续发展提供依据。其核心目标就是通过理解生命过程与地球环境相互作用的过程,评估人类对自然平衡和自然循环造成的影响,进而实施地球管理,确保地球生命支持系统的可持续发展。基于当前地球系统科学研究前沿,提出了未来关于地球环境与生命过程研究需 要重视的方面,尤其是关于生态系统对全球变化响应的阈值研究应引起高度重视。     

生命起源、早期演化阶段与海洋环境演变

近年的研究表明,地球生命可能起源于距今39~36亿年之间。除了碳元素以外,水、氮、氢、磷等元素也是生命起源的必备条件,黏土矿物和金属硫化物是有机质合成的重要催化剂,有热液活动的碱性热水环境是最有利生命发生的孵化场。自原核生物在约3.5 Ga出现之后,生命就一直表现为与环境的协同进化关系。大气圈氧化是地球史上最重大的地质事件之一,它不仅改变了地球表层环境条件、加速了表生地质过程和新矿物的产生,而且改变了海洋化学条件和元素循环。大气圈氧化事件的根本在于产氧蓝细菌的出现,元古宙中期海洋化学性质的整体转换也与微生物过程密切相关。新元古代多细胞生物的繁盛和末期后生动物的出现及其在寒武纪初期的快速多样化是生物圈演化的重大飞跃。这个过程也与海洋氧化增强及其导致的海洋化学变化密切相关,其中硫化水域消失和减弱以及海水中微营养元素可得性增加可能是重要因素,这也与微生物过程直接相关。     

Impact cratering — fundamental process in geoscience and planetary science

Impact cratering is a geological process characterized by ultra-fast strain rates, which generates extreme shock pressure and shock temperature conditions on and just below planetary surfaces. Despite initial skepticism, this catastrophic process has now been widely accepted by geoscientists with respect to its importance in terrestrial — indeed, in planetary — evolution. About 170 impact structures have been discovered on Earth so far, and some more structures are considered to be of possible impact origin. One major extinction event, at the Cretaceous-Paleogene boundary, has been firmly linked with catastrophic impact, but whether other important extinction events in Earth history, including the so-called “Mother of All Mass Extinctions” at the Permian-Triassic boundary, were triggered by huge impact catastrophes is still hotly debated and a subject of ongoing research. There is a beneficial side to impact events as well, as some impact structures worldwide have been shown to contain significant (in some cases, world class) ore deposits, including the gold-uranium province of the Witwatersrand basin in South Africa, the enormous Ni and PGE deposits of the Sudbury structure in Canada, as well as important hydrocarbon resources, especially in North America. Impact cratering is not a process of the past, and it is mandatory to improve knowledge of the past-impact record on Earth to better constrain the probability of such events in the future. In addition, further improvement of our understanding of the physico-chemical and geological processes fundamental to the impact cratering process is required for reliable numerical modeling of the process, and also for the correlation of impact magnitude and environmental effects. Over the last few decades, impact cratering has steadily grown into an integrated discipline comprising most disciplines of the geosciences as well as planetary science, which has created positive spin-offs including the study of paleo-environments and paleo-climatology, or the important issue of life in extreme environments. And yet, in many parts of the world, the impact process is not yet part of the geoscience curriculum, and for this reason, it deserves to be actively promoted not only as a geoscientific discipline in its own right, but also as an important life-science discipline.     

Half a century of progress in research on terrestrial impact structures: A review

The author, who investigated the Wolfe Creek, Australia, in 1962 and edited two Benchmark Sets of Readings on Meteorite Craters and possible Astroblemes in 1977 and 1979, reviews the state of knowledge at the present time. The text is concerned with terrestrial impact structures, geological features, without any consideration of extraterrestrial analogues. A handful of definitive publications are drawn on to present the story of terrestrial impact in a single article. The text covers historical aspects (briefly); the effect of target variations; the paucity of human observation of such large-scale events; distinction from volcanic (endogenous) structures; modification by geological processes; the transience of the crater initially formed on the target, and its subsequent modifications; the global geographic distribution of the 174 structures now listed (of which a number are dubious attributions); their distribution in geological time (many ages being known only known to wide limits, maximum or minimum values); their size distribution; calculations of impact frequencies; shock effects; processes on impact; the stages of formation; impact into shallow marine and deep sea targets; impacts on ice (about which little is known); and finally the input of impact into biotic extinctions. In this last lengthy section, the summaries of the conclusions of scientists researching impact on Earth and palaeontologists researching biotic impact are set side by side. It is concluded that, if the recent foraminiferal evidence obtained by Gerta Keller and associates is taken at its face value, the case of impact as a sole agent in extinction is non-existent: biotic extinction is clearly a complex process involving a number of causes, in some cases it was staggered in time, and different sets of organisms responded quite differently and surprisingly, even in the same extinction event. Extraterrestrial impact may have been one of the causes in some cases, but it may have been regional rather than global in its effects. We may never know how much input it had into the record of biotic extinction on Earth? An enormous amount of new knowledge has arisen from detailed studies of this new family of remarkable geological structures.     

Progress and Prospect in Deep Biosphere Investigation

The discovery of living microorganisms deep in the marine sediments and even in the oceanic crust (the marine “deep biosphere”), is one of the most significant and exciting discoveries since the ocean drilling program began almost a half-century ago. Investigation of the deep biosphere has become the most thrilling research frontier for both geological and biological sciences. The “biosphere frontiers” has been listed as one of the four themes in the 10-year plan of the International Ocean Discovery Program (IODP 2012-2023), including deep life, biodiversity and environmental forcing of ecosystems. Here, we introduced the deep biosphere and its environmental features, several completed Integrated Ocean Drilling Program Expeditions, which targeted the subseafloor deep biosphere within the crust and sediments, and highlighted the main progress we have made in deep biosphere and deep life research, especially the contribution of Chinese scientists. Finally, we will give a perspective on the future of deep biosphere research according to the challenge we are facing and the key questions need to be answered.     

Thirty Years of the Seafloor CORK Borehole Observatories: Development,Applications and Future Perspective

In the past 50 years, we have witnessed remarkable progress in our understanding of the Earth and ocean system, as a result of the internationally integrated deep ocean drilling programs, the Deep Sea Drilling Program (DSDP), the Ocean Drilling Program (ODP), and the Integrated Ocean Drilling Program (IODP). One of the legacies of the deep ocean drilling programs is the development and applications of the CORK, Circulation Obviation Retrofit Kit. Earth and ocean sciences have been shifting from a traditional discontinuous, expeditionary mode toward a mode of sustained in situ observations today. The seafloor CORK observatories offer Earth, ocean and life scientists new opportunities to study multiple, interrelated deep marine subsurface processes, over time scales ranging from seconds to decades. Here, we first provided a concise examination of the development history of the CORKs, then described the first installations of ODP CORKs, the evolution of different models of CORK, and finally, summarized the scientific lessons learned in the installation and operation effort of the CORKs. In the end, we offered our perspectives on using CORKs to study geological, hydrogeological, microbiological, and biogeochemical processes in the deep marine subsurface biosphere, particularly pertaining to China’s efforts in establishing and enhancing its deep-sea and deep-biosphere research and monitoring programs.     

Pillow lavas as a habitat for microbial life

The upper oceanic crust consists predominantly of pillow lavas that, soon after their eruption, are colonized by microbes when the ambient temperature ameliorates. During the process of microbial interaction with the glassy rims of pillows several types of bio-traces are generated, of which micro-textures are the most spectacular. Microbial textures are most useful for mapping the depth of the oceanic biosphere, and in the search for the earliest life on Earth.